Fan and motor drive device thereof

Abstract

A fan and a motor drive device thereof are provided. The motor drive device is configured to drive a motor and includes a control management unit and a voltage converter. The control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed ranges, each corresponding to a specific output duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to one of the rotation speed ranges in which the target rotation speed signal transmitted from the ECU falls. The voltage converter is connected between a power source and the motor, and is configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor.

The invention claimed is: 
     
       1. A motor drive device to drive a motor, comprising:
 a control management unit, configured to classify target rotation speed signals provided by an ECU into a plurality of rotation speed ranges, each corresponding to a specific output duty ratio, the control management unit is configured to receive a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to the rotation speed range to which the target rotation speed signal transmitted from the ECU falls; and 
 a voltage converter, connected between a power source and the motor, and configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor; 
 wherein the voltage converter comprises a diode and an MOS transistor connected between a positive electrode of the power source and ground in series, a cathode of the diode is connected to the positive electrode of the power source, an anode of the diode is connected to a drain of the MOS transistor, and a source of the MOS transistor is grounded, a gate of the MOS transistor receives the voltage regulating signal outputted from the control management unit, and the anode and the cathode of the diode are configured to be connected to the motor. 
 
     
     
       2. The motor drive device of  claim 1 , wherein the control management unit is configured to classify the target rotation speed signals provided by the ECU into four rotation speed ranges, which are a stalling range, a low-speed range, a middle-speed range and a full-speed range. 
     
     
       3. The motor drive device of  claim 1 , wherein the control management unit is configured to classify the target rotation speed signals provided by the ECU into three rotation speed ranges, which are a stalling range, a low-speed range and a full-speed range, and a duty ratio of the voltage regulating signal corresponding to the low-speed range ranges from 20% to 80%. 
     
     
       4. The motor drive device of  claim 1 , wherein the control management unit comprises:
 a command manager configured to determine the rotation speed range to which the target rotation speed signal transmitted from the ECU falls, and output a target voltage in an analog form based on the duty ratio corresponding to the rotation speed range; 
 a speed manager, connected with the command manager and the motor, and configured to compare the target voltage with a current voltage outputted to the motor and output a control signal based on a comparison result; and 
 a PWM generator, configured to output a voltage regulating signal for regulating the rotation speed of the motor in response to the control signal. 
 
     
     
       5. The motor drive device of  claim 1 , further comprising
 a gate driver, wherein the gate driver is connected between the control management unit and the voltage converter, and is configured to perform power amplification on the voltage regulating signal outputted from the control management unit and output to the MOS transistor. 
 
     
     
       6. The motor drive device of  claim 1 , further comprising a sampling resistor for collecting a current flowing through the motor, wherein
 the control management unit further comprises a locked-rotor manager, and the locked-rotor manger is configured to acquire an operation state of the motor by collecting a voltage between two ends of the sampling resistor, and enable the motor to be driven in a case of locked-rotor. 
 
     
     
       7. The motor drive device of  claim 1 , further comprising
 a filtering unit connected between the power source and the voltage converter, and configured to filter out noise of a voltage to the voltage converter. 
 
     
     
       8. The motor drive device of  claim 1 , further comprising
 a printed circuit board, wherein the control management unit and the voltage converter are arranged on the printed circuit board. 
 
     
     
       9. The motor drive device of  claim 2 , wherein
 the target rotation speed signal is in the stalling range in a case that a duty ratio of the target rotation speed signal is less than a ratio value X 1 , which is less than 10%, 
 the target rotation speed signal is in the low-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio valve X 1  and less than a ratio value X 2 , which is greater than the ratio valve X 1  and less than or equal to 50%, 
 the target rotation speed signal is in the middle-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio valve X 2  and less than a ratio value X 3 , which is greater than the ratio valve X 2  and less than or equal to 90%, and 
 the target rotation speed signal is in the full-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio value X 3  and less than 100%. 
 
     
     
       10. The motor drive device of  claim 8 , further comprising a case with a connector mounted thereon, wherein the printed circuit board is accommodated in the case, the connector comprises a first input terminal, a second input terminal and a third input terminal, one end of the first input terminal being connected to a negative electrode of the power source, one end of the second input terminal is connected to a positive electrode of the power source, one end of the third input terminal is connected to the ECU, and the other end of each of the first input terminal, the second input terminal and the third input terminal is inserted into the printed circuit board. 
     
     
       11. The motor drive device of  claim 9 , wherein the ratio value X 1  is less than or equal to 5%. 
     
     
       12. The motor drive device of  claim 9 , wherein the ratio value X 2  is less than or equal to 40%. 
     
     
       13. The motor drive device of  claim 9 , wherein the ratio value X 3  is less than or equal to 80%. 
     
     
       14. The motor drive device of  claim 9 , wherein a duty ratio of the voltage regulating signal corresponding to the stalling range is equal to 0,
 a duty ratio of the voltage regulating signal corresponding to the low-speed range is equal to a ratio value Y 1 , which is greater than or equal to 20% and is less than or equal to 50%, 
 a duty ratio of the voltage regulating signal corresponding to the middle-speed range is equal to a ratio value Y 2 , which is greater than or equal to 50% and less than or equal to 80%, and 
 a duty ratio of the voltage regulating signal corresponding to the full-speed range is equal to 100%. 
 
     
     
       15. The motor drive device of  claim 10 , wherein the connector further comprises a first output terminal and a second output terminal configured to connect the voltage converter on the printed circuit board with the motor, and the first output terminal and the second output terminal are connected to the motor by wires. 
     
     
       16. A fan, comprising
 a fan housing, 
 a motor installed in the fan housing, 
 an impeller driven by the motor, and 
 the motor drive device, comprising:
 a control management unit, configured to classify target rotation speed signals provided by an ECU into a plurality of rotation speed ranges, each corresponding to a specific output duty ratio, the control management unit is configured to receive a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to the rotation speed range to which the target rotation speed signal transmitted from the ECU falls; and 
 a voltage converter, connected between a power source and the motor, and configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor; 
 the voltage converter comprises a diode and an MOS transistor connected between a positive electrode of the power source and ground in series, a cathode of the diode is connected to the positive electrode of the power source, an anode of the diode is connected to a drain of the MOS transistor, and a source of the MOS transistor is grounded, a gate of the MOS transistor receives the voltage regulating signal outputted from the control management unit, and the anode and the cathode of the diode are configured to be connected to the motor. 
 
 
     
     
       17. The fan of  claim 16 , wherein the motor drive device is arranged on the fan housing.